1. Field of the Invention
This invention relates to explosion vent openings for industrial storage and process buildings.
Industries, utilizing dust and vapor handling equipment, are faced with a continuous explosion potential.
Dust and vapor explosions are the result of rapid release of energy generated virtually instantaneously. This occurs either by rapid oxidation or by the development of internal pressure beyond the confinement capability of the enclosure causing it to rapidly and fully open.
Explosion venting is a protective measure of explosion pressure relief. Venting is intended to prevent the destruction of an enclosure due to an over pressured condition caused by dust or vapor explosion. It is also a protection measure to prevent the exploding of an enclosure due to other resultant over pressured caused by mechanical system failures.
2. Description of the Prior Art
There are explosive vents on the market based on rupture disc panels, such as is disclosed by U.S. Pat. No. 4,067,154. This patent depends upon the breading of a membrane or panel to form a vent opening. A rupture membrane has several disadvantages, such as: replacing a membrane approximately 3 ft..times.4 ft. would cost approximately $800.00; also, the accuracy of a membrane rupturing is extremely limited and when ruptured, does not fully tear; the accuracy of a breaking membrane system is extremely low, being rated as having an accuracy of plus or minus one-half of one psi with a standard opening pressure of between 1 to 4 psi above atmospheric pressure; and, another disadvantage of a membrane is that is must operate within 50% of the actual burst pressure for the reason a membrane is subject to fatigue and if it does operate near its bursting pressure, it will always burst prematurely.
Other latch devices are available for door type venting such as a latch utilizing a spring loaded cam presently marketed by the Brixon Manufacturing Company of St. Paul, Minn. 55114. However, this particular latch requires constant maintenance and is subject to corrosive action and lacks the accuracy desired in a vent door explosion release apparatus.
This invention obviates the above disadvantages by providing a collapsible or pressure release rupture pin collapsed by axially applied pressure which permits accurate calibration of its failure value. Further, replacement cost of the rupture pin approximates $10.00. Also, a rupture pin release explosion vent door prevents the door to fully open and therefore provides a greater venting volume of explosion gases.